A liquid crystal display (LCD) is one of the most widely used flat panel displays. A LCD is a display device that can adjust the amount of transmitted light by applying a voltage to an electrode formed by interposing a liquid crystal layer between two display panels and realigning liquid crystal molecules of the liquid crystal layer.
An example of a currently-used liquid crystal display (LCD) has a structure where a field generating electrode is respectively mounted in the two display panels. Specifically, in the main structure, a plurality of thin film transistors and a pixel electrode are aligned in a matrix form in one display panel (hereinafter, referred to as ‘a thin film transistor array panel’), while red, green and blue color filters are formed in the other display panel (hereinafter, referred to as ‘a common electrode panel’), and a common electrode covers the foreside (front surface) thereof.
However, since the pixel electrodes and the color filters are formed in different display panels, it can be difficult to precisely align the same, and the resultant liquid crystal display (LCD) may have an alignment error. In order to solve this problem, a structure in which the color filters and the pixel electrode are formed on the same display panel (color filter on array, COA) has been proposed.
As another option, when a thin film transistor array panel is aligned with a common electrode panel, a light-blocking layer can be formed to be larger than a predetermined size, based on an align margin.
In addition, a liquid crystal layer space between the two display panels is referred to as a cell gap, and the cell gap has an influence on overall operation characteristics of the liquid crystal display (LCD) such as response speed, contrast ratio, viewing angle, luminance uniformity and the like. When the cell gap is not uniform, a uniform image is not displayed all over a screen, causing an image quality defect.
Accordingly, there is a need for a liquid crystal display (LCD) that can prevent deterioration of an aperture ratio due to the increased size of a light-blocking layer and can maintain a uniform cell gap all over the foreside of a substrate.